110 Dr. A. S. Packard, Jr' Revision of the 



transverse, oblong. The clypeal region is much broader and shorter pro- 

 portionately, the eyes are larger and more globose, the front is broader 

 and flatter. The prothorax is angulated on the sides, and the pteros- 

 tmma is much more distinct than usual, while the outer side of the 

 submedian cell, is oblique, where in 0. Q-maculatus it is straight, also 

 the second median recurrent terminates near the middle of the first 

 subcostal cell, where in 0. 6-maculatits it as usual joins the end of the 

 space, also the legs are much stouter and more spiney than usual. 

 In some of these characters such as the broad head and flattened body 

 the 9 remind us of TIn/reopus. but a glance at the pinched, deeply 

 channelled tip of the abdomen will easily enable the species to be 

 separated. 



Group I. 



Crabro septentrionalis, n. sp. 



9 . Head short, broad, transversely oblong, being one-half as long 

 as broad, body long and flattened, finely punctured, vertex flattened, 

 slightly depressed ; ocelli arranged in a low triangle which is nearly 

 equilateral; eyes wide apart as usual; surface concave in front of the 

 ocelli ; antennal groove well marked ; orbits on each side lined with 

 a broad track of golden pubescence like the clypeal region ; clypeus 

 as long as broad, acutely produced on the front edge, but truncate at 

 tip, strongly carinated, black ; mandibles as usual bidentate, yellow, 

 black at tip. Antennae of the usual proportion, scape a little com- 

 pressed and angulated longitudinally, slightly dilated in the middle, 

 entirely yellow; flagellum black, basal joint yellowish beneath, abdo- 

 men ferruginous. 



Prothorax with two narrow yellow stripes, rather remote, one on 

 each side. Thorax broad somewhat flattened above; on mesoscutum 

 are two distinct submesial ridges and parapsidal grooves; surface 

 finely and closely punctured ; a slight yellow spot, sometimes absent, 

 on the middle of the meta-scutellum. Tubercle on the flanks as usual. 

 Enclosure on propodeum distinctly marked, semi-elliptical, mesial fur- 

 row with slightly ridged sides, on each side straight diverging rugae 

 of unequal length, posteriorly the lines more transverse and finer with 

 a few ssattered gray hairs. Tegulae ferruginous, nervures dull ferru- 

 ginous. Fore femora black, tibia? yellow, ferruginous within, tarsi yellow 

 shaded on the sides with pale ferruginous, middle femora black, yel- 

 low at tip beneath, tibiae yellow with a large oval black spot within, 

 hind pair tuberculated and unusually spinulated ; tarsi yellowish, un- 

 gues ferruginous; hind femora black, lined within with a silvery 



